Film forming compositon

ABSTRACT

The present application relates to a film forming composition for application to mammalian skin, which composition comprises at least one polyurethane based polymer together with at least one acrylate based polymer. The film forming composition provides effective skin coating with good adhesion to the skin, and may be used as a skin protector or a wound dressing.

The present invention relates to a protective film composition which finds particular utility in forming a film over mammalian skin.

Existing films suitable for application to the skin are based on cyanoacrylate chemistry as is commonly used in superglue. Unsurprisingly, these films share many of the characteristics of superglue, in particular they actually stick skin together. Clearly this is undesirable for a product intended to be used on the skin. Moreover, extreme care is required during its application to the skin. The product also has limited applications in terms of the areas to which it can be applied. The product also tends to require an applicator and in some cases further mixing with chemicals is required. Furthermore, once exposed to air, these products tend to “go off” very rapidly and as such have a short lifespan.

Other non-cyanoacrylate based products include Cavilon® which is based on a silicone polymer and Nu-Skin® which is a nitrocellulose based compound comprising ethyl acetate and ethanol.

Although Cavilone® provides a water-proofing effect it is difficult to apply effectively as the user cannot be sure that a complete coat has been achieved. Furthermore, Cavilon® is a particularly expensive product.

As Nu-Skin® is nitrocellulose based it has a disagreeable odour. Furthermore, the product is unsuitable for application to open wounds as it causes the wound to sting. The product gives rise to a heavy coating which tends to crack and flake within one or two hours of application. Therefore, the product is uncomfortable to ‘wear’ and as frequent reapplication is necessary it is uneconomical.

In addition to the foregoing products there are several generic products available which use a silicone fluid. These products are essentially waterproofing barrier creams/lotions. However, the products do not form a film upon the skin and as such tend to wash/wear off within 24 or 48 hours.

Therefore, it is desirable to provide a composition which forms a film upon mammalian skin which in doing so provides a long lasting waterproofing effect and yet which is mild enough to be applied to open wounds without causing stinging.

According to the first aspect of the present invention there is provided a film forming composition for application to mammalian skin or a breach in the skin comprising at least one polyurethane based polymer together with at least one acrylate based polymer.

Advantageously, the composition of the present invention is in liquid form thus facilitating its application to the skin. It provides an effective skin coating with good adhesion to the skin. Furthermore, the composition is preferably clearly visible once applied in order to assist application and ensure that a desired area is completely covered. Application of the composition does not require a separate applicator.

The composition may also be safely applied to breaches in the skin, such as wounds. Advantageously, the composition can be applied to an open wound without causing stinging. Moreover, if the wound has exposed nerve endings the protective film quickly seals the wound such that a reduction in pain is observed.

The composition of the present invention is easy to apply and does not stick skin together.

Therefore, the composition of the present invention can be used as a skin protector on intact skin or as a wound dressing for application directly onto a wound.

Thus, according to a second aspect of the present invention there is provided a polymeric protective film obtainable by applying to mammalian skin or a breach in the skin a film forming composition comprising at least one polyurethane based polymer together with at least one acrylate based polymer.

The film forming composition may typically be applied to the skin or a breach in the skin in the form of a liquid, cream, emulsion, gel or paste. The composition dries in situ to form a protective film. The composition may dry to form a protective skin within around 10 minutes or less. In some embodiments, the drying time may be around 5 minutes or less, and in some embodiments drying of the composition may take around 3 minutes or less.

According to a further aspect of the present invention there is provided the use of a film forming composition comprising at least one polyurethane based polymer together with at least one acrylate based polymer as a skin protector.

According to a still further aspect of the present invention there is provided the use of a film forming composition comprising at least one polyurethane based polymer together with at least one acrylate based polymer as a wound dressing.

Said polyurethane based polymer comprises a polyurethane or polyurethane derivative. Said polyurethane based polymer may be in the form of an emulsion, a fluid suspension, a solution or any combination thereof.

Polyurethane based polymers suitable for use with the present invention include any of the following either alone or in combination: polyurethane, polyetherpolyurethane, polyureapolyurethane, copolymers of polyurethane, polyurethane/silicone copolymers, polyurethane/acrylic copolymers, polyurethane adhesives, polyurethane derivatives, polyurethane elastomers, polyurethane prepolymers, polyurethane hydrogels.

It is to be understood that the foregoing examples are provided by way of example only and the invention is not intended to be limited thereby.

Said polyurethane based polymer may constitute from 0.1% to 99.9% w/w, preferably from 0.5% to 99.5% w/w, more preferably from 2.5% to 97% w/w, still more preferably from 10% to 90% w/w and most preferably from 50% to 75% w/w of the total composition.

Said acrylate based polymer comprises any suitable acrylate or acrylic derivative. Said acrylate based polymer may be in the form of an emulsion, a fluid suspension, a solution or any combination thereof.

Acrylic based polymers suitable for use with the present invention include any of the following either alone or in combination: polyacrylic acid, carbomer, carboxyvinyl polymer, carboxypolymethylene polymer, polyacrylate elastomers, polyacrylates, polyacrylate copolymer, polyacrylate crosspolymers, acrylates/alkyl acrylate crosspolymer, AMP-acrylates/Allyl Methacrylate Copolymer, acrylates/acrylamide copolymer, acrylic acid/alkyl methacrylate copolymer, silicone/acrylates copolymer, acrylates/polyurethane copolymer.

It is to be understood that the foregoing examples are provided by way of example only and the invention is not intended to be limited thereby.

Said acrylate based polymer may constitute from 0.1% to 99.9% w/w, preferably from 0.5% to 99.5% w/w, more preferably from 2.5% to 97% w/w, still more preferably from 10% to 90% w/w and most preferably from 25% to 50% w/w of the total composition.

The composition of the present invention may also comprise any of the following either alone or in combination: viscosity enhancing compounds including but not limited to carbomers and viscosity enhancing salts, such as sodium chloride and similar salts; polyols; solvents; volatile solvents; antimicrobials including but not limited to silver salts, silver complexes, chlorhexidine, benzalkonium halides; agents for adversely affecting biofilms; adhesives; preservatives; waterproofing agents; growth factors; healing agents; surfactants; moisturisers; herbal extracts, amino acids, pH altering compounds; cleansers; haemostats; other skin adhesives; and other film forming compounds.

In preferred embodiments, water is used as a solvent. Advantageously, this avoids the use of solvents which can cause stinging or pain when applied to a wound or other breach in the skin.

Surprisingly, the composition of the present invention has been found to be resistant to gamma sterilisation, in that the viscosity of the composition is not significantly adversely affected by the gamma radiation. In contrast to this, currently available film forming compositions are not resistant to gamma sterilisation and their film forming properties tend to be compromised as a result of their exposure to gamma radiation. Advantageously, gamma irradiation of the compositions according to aspects of the present invention may result in compositions which dry on skin to form more robust films when compared to non-irradiated compositions.

Clearly the ability of the compositions of the present invention to be sterilised renders them suitable for application in a wider range of wounds types and gives access to additional market areas.

Thus, according to a further aspect of the present invention there is provided a method for the preparation of a sterile film forming composition for application to mammalian skin or a breach in the skin comprising the steps of: mixing together a polyurethane based polymer and an acrylate based polymer, and irradiating the resulting mixture using gamma radiation.

According to a further aspect of the present invention there is provided a sterile film forming composition for application to mammalian skin or a breach in the skin, obtainable by mixing together a polyurethane based polymer and an acrylate based polymer, and irradiating the resulting mixture using gamma radiation.

Typically, the composition according to aspects of the present invention is provided as a liquid, cream, emulsion, gel or paste.

It is envisaged that the composition may also be available in the form of a skin wipe. In this embodiment the composition of the present invention is absorbed onto a suitable fibrous material such as a cellulose material.

It is also envisaged that the composition may be in the form of a spray.

The present invention will now be described further by way of example only and with reference to the following examples:

EXAMPLE 1

Material Description Concentration Avalure AC 118 Acrylic based polymer in 50% solution Avulure UR 425 Polyurethane based polymer 50% in solution

The two components are mixed together at room temperature using a stirrer for 15 minutes. The resulting white liquid can be easily spread on to skin and dries to give a uniform visible film barrier.

The film barrier adheres well to the skin and remains intact and in place for over 24 hours protecting the skin from external factors.

EXAMPLES 2 TO 5

Components Example 2 Example 3 Example 4 Example 5 Avalure AC 100%  0% 25% 25% 118 Avulure UR  0% 100% 50% 50% 425 Water None None 25% 25% Sterilised? No No No Yes. Gamma 25 kgry Drying Time 2 mins 2.5 mins 4 mins 4 mins Film format Does not form a Forms a discrete Forms a discrete Forms a discrete coating film, but the film robust film with discrete on the skins is weak and good adherence robust film surface. Can not adherence to the to the skin with good be removed or skin is also adherence to peeled off. weak. the skin Wear time Coating offers Film begins to 24 hours before 24 hours or exposed no protect from fall off almost any cracking. before any film. moist external immediately. Main bulk of the cracking. factors. film last for a Main bulk of further 2 days. the film last for a further 3 days. Adhesion of Good Good but film Good Good dressing to lift easily off film/skin skin and dressing falls off

EXAMPLES 6 TO 9

Components Example 6 Example 7 Example 8 Example 9 Avalure AC 33.3%   25% 25%   25% 120 Avulure UR 67.7%   50% 50%   50% 425 Water None 24.7% 25% 24.8% Carbomer None  0.3% None None Silver None None None  0.2% Nitrate Sterilised? No Yes. Yes. No Gamma 25 kgry Gamma 25 kgry Drying 2 mins 3.5 mins 4 mins 4 mins Time Film format Forms a Forms a discrete Forms a discrete Forms a discrete discrete robust robust film with robust film with slightly film with good good adherence good adherence to coloured robust adherence to the to the skin. the skin film with good skin. adherence to the skin Wear time 24 hours before 24 hours before 24 hours before 24 hours before or exposed any cracking. any cracking. any cracking. any cracking. film. Main bulk of Main bulk of the Main bulk of the Main bulk of the the film last for film last for a film last for a film last for a a further 2 days. further 2 days. further 2 days. further 3 days. Adhesion of Good Good Good Good dressing to film/skin

EXAMPLES 10 TO 13

Components Example 10 Example 11 Example 12 Example 13 Avalure AC   5%   23% 49.5% 49.975% 120 Avulure UR  95%   50%   50%    50% 425 Water None 24.7% None None Carbomer None  0.3% None None Calcium 0.1% None None chloride Hyaluronic None None None  0.025% Acid Glycerol None   2% None None Waterproofing None None 0.25% Silicone None agent (silicone oil emulsion) 0.25% Novemer EC-1 Sterilised? Yes Yes. No No Gamma 25 Kgy Gamma 25 kgry Drying Time 2 mins 4.5 mins 3.5 mins 2.5 mins Film format Forms a discrete Forms a discrete Forms a discrete Forms a robust film with robust film with robust film with discrete good adherence good adherence to good adherence slightly to the skin. The the skin. The film to the skin. coloured film contains contains a robust film calcium ions humectant/ with good which are know moisturiser adherence to to have a (glycerol) and is the skin beneficial effect softer and more on the intrinsic flexible. blood clotting cascade. Wear time or 24 hours before 36 hours before 24 hours before 24 hours exposed film. any cracking. any cracking. any cracking. before any Main bulk of the Main bulk of the Main bulk of the cracking. film last for a film last for a film last for a Main bulk of further 2 days. further 1 day. further 2 days. the film last for a further 2 days. Adhesion of Good. Acceptable Acceptable Good dressing to film/skin

EXAMPLES 14 TO 17

Sodium chloride was dissolved in water. The two polymer components were mixed together at room temperature using a stirrer for 15 minutes, The salt solution was added to the polymer mixture and the combination stirred for 1 hour. The resulting white product can be easily spread on to skin and dries to give a uniform visible film barrier. Product made with above 0.3% sodium chloride showed an increase in viscosity which was apparent to an observer. This viscosity increase developed over a period of a few hours.

The film barrier adheres well to the skin and remains intact and in place for over 24 hours protecting the skin from external factors. The film barrier from product containing over approximately 0.45% sodium chloride is distinctly stronger and more robust.

Components Example 14 Example 15 Example 16 Example 17 Avalure AC  46%   46%  46%  46% 118 Avulure UR  46%   46%  46%  46% 425 Water 7.7%  7.7% 7.7% 7.7% Sodium 0.3% 0.45% 0.6% 0.9% Chloride Sterilised? No No No No Format Liquid Thick liquid Cream Semi solid emulsion Drying Time 3 mins 3 mins 3 mins 3.5 mins Film format Forms a Forms a Forms a Forms a distinct robust distinct robust distinct very discrete very film with good film with good robust film robust film adherence to adherence to with good with good the skin the skin adherence to adherence to the skin the skin Wear time or 24 hours 24 hours 48 hours 48 hours exposed film. before any before any before any before any cracking. cracking. cracking. cracking. Main bulk of Main bulk of Main bulk of Main bulk of the film last for the film last for the film last for the film last for a further 2 a further 2 a further 2 a further 3 days. days. days. days. Adhesion of Good Good Good Good dressing to film/skin

EXAMPLES 18 TO 21

Sodium chloride was dissolved in the water. The two polymer components were mixed together at room temperature using a stirrer for 15 minutes. The salt solution and glycerol were added to the polymer mixture and the combination stirred for 1 hour. The resulting white product can be easily spread on to skin and dries to give a uniform visible film barrier.

The film barrier adheres well to the skin and remains intact and in place for over 24 hours protecting the skin from external factors. The film barrier from product containing glycerol is distinctly more robust.

Components Example 18 Example 19 Example 20 Example 21 Avalure AC  44%   44%  44%  44% 118 Avulure UR  44%   44%  44%  44% 425 Water 7.7%  7.7% 7.7% 7.7% Sodium 0.3% 0.45% 0.6% 0.9% Chloride Glycerol   4%   4%   4%   4% Sterilised? No No No No Format Liquid Thick liquid Cream Semi solid emulsion Drying Time 3 mins 3 mins 3 mins 3.5 mins Film format Forms a Forms a Forms a Forms a distinct robust distinct robust distinct very discrete very film with good film with good robust film robust film adherence to adherence to with good with good the skin the skin adherence to adherence to the skin the skin Wear time or 48 hours 48 hours 72 hours before 72 hours before exposed film. before any before any any cracking. any cracking. cracking. cracking. Main bulk of Main bulk of Main bulk of Main bulk of the film last for the film last for the film last the film last a further 2 a further 2 for a further for a further days. days. day. day. Adhesion of Good Good Good Good dressing to film/skin

EXAMPLES 22 TO 25

Sodium chloride was dissolved in the water. The two polymer components were mixed together at room temperature using a stirrer for 15 minutes. The salt solution was added to the polymer mixture and the combination stirred for 1 hour.

The resulting product was gamma sterilised with a nominal dose of 25 kgry.

The resulting white product can be easily spread on to skin and dries to give a uniform visible film barrier. The gamma sterilised product does not lose viscosity.

The film barrier adheres well to the skin and remains intact and in place for over 24 hours protecting the skin from external factors. The film barrier from gamma sterilised product is distinctly stronger and more robust.

Components Example 22 Example 23 Example 24 Example 25 Avalure AC  46%   46%  46%  46% 118 Avulure UR  46%   46%  46%  46% 425 Water 7.7%  7.7% 7.7% 7.7% Sodium 0.3% 0.45% 0.6% 0.9% Chloride Sterilised? yes yes yes yes Format before Liquid Thick liquid Cream Semi solid gamma emulsion Format after Liquid Thick liquid Cream Semi solid gamma emulsion Drying Time 3 mins 3 mins 3 mins 3.5 mins Film format Forms a Forms a Forms a Forms a distinct very distinct very distinct very discrete very robust film robust film robust film robust film with good with good with good with good adherence to adherence to adherence to adherence to the skin the skin the skin the skin Wear time or 48 hours 48 hours 72 hours before 72 hours before exposed film. before any before any any cracking. any cracking. cracking. cracking. Main bulk of Main bulk of Main bulk of Main bulk of the film last for the film last for the film last the film last a further 2 a further 2 for a further for a further days. days. day. day. Adhesion of Good Good Good Good dressing to film/skin

EXAMPLES 26 TO 29

Sodium chloride was dissolved in the water. The two polymer components were mixed together at room temperature using a stirrer for 15 minutes. The salt solution and glycerol were added to the polymer mixture and the combination stirred for 1 hour.

The resulting white product was gamma sterilised with a nominal dose of 25 kgry and showed no loss of viscosity.

The product dries to give a film barrier which adheres well to the skin and remains intact and in place for over 48 hours protecting the skin from external factors. The film barriers from sterilised product containing glycerol are distinctly more robust.

Components Example 26 Example 27 Example 28 Example 29 Avalure AC  44%   44%  44%  44% 118 Avulure UR  44%   44%  44%  44% 425 Water 7.7%  7.7% 7.7% 7.7% Sodium 0.3% 0.45% 0.6% 0.9% Chloride Glycerol   4%   4%   4%   4% Sterilised? yes yes yes yes Format before Liquid Thick liquid Cream Semi solid gamma emulsion Format after Liquid Thick liquid Cream Semi solid gamma emulsion Drying Time 3 mins 3 mins 3 mins 3.5 mins Film format Forms a Forms a Forms a Forms a distinct very distinct very distinct very discrete very robust film robust film robust film robust film with good with good with good with good adherence to adherence to adherence to adherence to the skin the skin the skin the skin Wear time or 72 hours 72 hours 72 hours before 72 hours before exposed film. before any before any any cracking. any cracking. cracking. cracking. Main bulk of Main bulk of Main bulk of Main bulk of the film last for the film last for the film last the film last a further 2 a further 3 for a further for a further days. days. day. day. Adhesion of Good Good Good Good dressing to film/skin

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments which are described by way of example only. 

The invention claimed is:
 1. A gamma radiation sterilized sterile liquid film forming composition for application to mammalian skin or a breach in the skin comprising 10-90% w/w at least one polyurethane based polymer, 25-50% w/w of at least one acrylate based polymer and a solvent comprising water, wherein the composition is in liquid form upon application, and dries in situ to form a discrete uniform film on application to mammalian skin or a breach in the skin.
 2. A film forming composition according to claim 1, wherein, in use, said composition dries in situ in less than 10 minutes to form a film on mammalian skin.
 3. A film forming composition according to claim 1, wherein said polyurethane based polymer is in the form of an emulsion, a fluid suspension, a solution or any combination thereof.
 4. A film forming composition according to claim 1, wherein said polyurethane based polymer is selected from the following either alone or in combination: polyurethane, polyetherpolyurethane, polyureapolyurethane, copolymers of polyurethane, polyurethane/silicone copolymers, polyurethane/acrylic copolymers, polyurethane adhesives, polyurethane derivatives, polyurethane elastomers, polyurethane prepolymers, polyurethane hydrogels.
 5. A film forming composition according to claim 1, wherein said polyurethane-based polymer constitutes from 50% to 75% w/w of the total composition.
 6. A film forming composition according to claim 1, wherein said acrylate based polymer is in the form of an emulsion, a fluid suspension, a solution or any combination thereof.
 7. A film forming composition according to claim 1, wherein said acrylate based polymer is selected from the following either alone or in combination: polyacrylic acid, carbomer, carboxyvinyl polymer, carboxypolymethylene polymer, polyacrylate elastomers, polyacrylates, polyacrylate copolymer, polyacrylate crosspolymers, acrylates/alkyl acrylate crosspolymer, AMP-acrylates/Allyl Methacrylate Copolymer, acrylates/acrylamide copolymer, acrylic acid/alkyl methacrylate copolymer, silicone/acrylates copolymer, acrylates/polyurethane copolymer.
 8. A film forming composition according to claim 1, wherein the composition further comprises any of the following either alone or in combination: viscosity enhancing compounds; polyols; solvents; volatile solvents; antimicrobials; preservatives; waterproofing agents; growth factors; healing agents; surfactants; moisturisers; herbal extracts; amino acids; pH altering compounds; cleansers; and haemostats.
 9. A film forming composition according to claim 8, wherein said viscosity enhancing compound is a viscosity enhancing salt.
 10. A film forming composition according to claim 9, wherein said viscosity enhancing salt is sodium chloride.
 11. A film forming composition according to claim 8, wherein said antimicrobial is selected from one or more of silver salts, silver complexes, antibiotics, zinc, copper, chlorhexidine, and benzalkonium halides.
 12. A film forming composition according to claim 1, wherein said composition is visible when applied to mammalian skin or a breach in the skin.
 13. A film forming composition according to claim 1 wherein said composition is provided with an applicator operable to facilitate the application of said composition to mammalian skin or a breach in the skin.
 14. A film forming composition according to claim 1, wherein said composition is in the form of a spray.
 15. A skin wipe comprising a film forming composition according to claim 1 adsorbed onto a fibrous material.
 16. A skin wipe according to claim 15, wherein said fibrous material is a cellulose material.
 17. A skin protector comprising a film forming composition according to claim
 1. 18. A wound dressing comprising a film forming composition according to claim
 1. 19. A polymeric protective film obtainable by applying to mammalian skin or a breach in the skin a film forming composition according to claim
 1. 20. A method of treating skin with a skin protector comprising the steps of: providing a polyurethane based polymer and an acrylate based polymer; mixing 10-90% w/w said polyurethane based polymer and 25-50% w/w of said acrylate based polymer and a solvent comprising water to form a liquid skin protector; irradiating the liquid skin protector with gamma radiation; and applying a therapeutically effective amount of said gamma irradiated, liquid skin protector to mammalian skin, wherein the gamma irradiated, liquid skin protector dries in situ and forms a discrete uniform film on application to mammalian skin.
 21. A method of treating a wound with a wound dressing comprising the steps of: providing a polyurethane based polymer and an acrylate based polymer; mixing 10-90% w/w said polyurethane based polymer and 25-50% w/w of said acrylate based polymer and a solvent comprising water to form a liquid wound dressing; irradiating the liquid wound dressing with gamma radiation; and applying a therapeutically effective amount of said gamma irradiated, liquid wound dressing to mammalian skin or a breach in said skin, wherein the gamma irradiated, liquid wound dressing dries in situ and forms a discrete uniform film on application to mammalian skin or a breach in said skin.
 22. A method for the preparation of a radiation sterilized sterile liquid film forming composition, comprising the steps of: mixing together 10-90% w/w of a polyurethane based polymer and 25-50% w/w of an acrylate based polymer and a solvent comprising water to form a liquid film forming composition, and irradiating the liquid film forming composition using gamma radiation, wherein the irradiated, liquid film forming composition dries in situ and forms a discrete uniform film on application to mammalian skin or a breach in the skin.
 23. A gamma radiation sterilized sterile liquid film forming composition for application to mammalian skin or a breach in the skin, obtainable by mixing together 10-90% w/w of a polyurethane based polymer and 25-50% w/w of an acrylate based polymer and a solvent comprising water to form a liquid film forming composition, and irradiating the resulting liquid film forming composition using gamma radiation, wherein the gamma irradiated, liquid film forming composition dries in situ to form a discrete uniform film on application to mammalian skin or a breach in the skin. 